The present invention relates to a disc cleaner which effectually wipes off dust or fingerprints, etc. from, for example, a digital audio disc (known commercially as a compact disc), an optical disc, etc.
For cleaning a digital audio disc, it is regarded as a taboo to wipe the disc off in the circumferential direction, and it is thought to be the correct manner to wipe the disc off in the diametrical direction. This is because pits carved in the disc in an elliptical shape are arranged in the line of the circumference of the disc. Therefore, even when the disc is wiped in the diametrical direction and a flaw or a scratch is formed on the surface of the disc, it only runs across the pits, which has little influence on the disc. On the contrary, when the disc is wiped in the circumferential direction thereof, the pits are affected and become to be defective, resulting in a lack of signals. Or, worse, adjacent pits may be flawed simultaneously all at one time.
Taking the above-described facts into consideration, a prior art disc cleaner which is arranged to wipe off the surface of the disc in the diametrical direction has already been proposed, for example, as shown in FIG. 38. According to this prior art device, an inner gear 540 and a planet gear 541, which revolves while rotating along the inner surface of the gear 540, constitute a cycloid mechanism in which any point on a ring-shaped cleaning pad 522 fixed to the planet gear 541 draws a trace or a locus P in the shape of a petal as the pad 522 wipes the surface of a stationary disc 503 (disclosed in the published specification of Japanese Utility Model Laid-Open No. 60-116604). The planet gear 541 is rotated by a driving gear 543 which is manually rotated.
Further, as shown in FIG. 37, another prior art disc cleaner of the above-described type has also been developed. The disc cleaner of FIG. 37 includes a mounting saucer 505 installed in a body casing 501 for placing a disc 503 thereon, a turntable 555 placed in the center of the mounting saucer 505, and a cleaner member 556 in the eccentric center of the mounting saucer 505, all of which are rotatably provided. In the aforementioned construction, when lid 502 is closed and a switch 557 is turned on, with the disc 503 put on the turntable 555 in the manner that its label surface faces up and the signal surface faces downward, the turntable 555 and the cleaner body 556 are rotated, so that the dust and dirt on the signal surface of the disc 503 can be wiped off by the cleaner member 556.
The cleaning pad 522 is attitude controlled by the utilization of the cycloid mechanism in the disc cleaner of FIG. 38, and accordingly, the entire cleaning mechanism is totally accommodated within the outline of the disc 503, resulting in the realization of a compact disc cleaner. On the other hand, since the rotation cycle of the cleaning pad 522 is extremely large in comparison with the revolution cycle thereof, the trace components along the circumferential direction of the disc 503 become increased, which will turn out to be a drawback in the case where the disc 503 is scratched. This results from the restrictions that the cleaning pad 522 is within a radius of the disc 503, and the rotational center of the planet gear 541 is positioned approximately at the center of the disc 503 in the radius of the disc 503, and consequently, the gear ratio of the inner gear 540 with respect to the planet gear 541 cannot be smaller than a specified predetermined value. In other words, the fact that the cleaning pad 522 is attitude controlled by the utilization of the cycloid mechanism of the inner gear type is disadvantageous from the viewpoint of obtaining a suitable trace of the pad.
Moreover, in the disc cleaner of FIG. 37, the turntable 555 and the cleaner member 556 are both placed at the side of the body casing 501, and therefore if the switch 557 is erroneously turned on, with the lid 502 being opened and the cleaner member 556 dropped on the disc 503 by mistake, it is feared that the disc 503 will be deformed or broken. There is also some fear in the prior art in handling of the disc. Further, the disc 503 is set on a mounting saucer 505 in the manner that the signal surface is turned down, while the label surface is turned up, and therefore, it is inconvenient according to the prior art, that how the signal surface is being cleaned cannot be confirmed during the cleaning of the disc 503. In addition, since the cleaning member 556 is disposed on the upper surface side of the body casing 501, the cleaning member 556 is undesirably easily covered with dust.